from tkinter import *
root = Tk()
root.title("ИТ марафон")
root.geometry("500x500")
c= Canvas(bg="white", width=250, height=250)
c.pack(anchor=CENTER, expand=1)
c.create_polygon(0,0,0,160,240,160,240,0,160,0,160,80,80,80,80,0,0,0)
root.mainloop()
